Nanocasting synthesis of mesoporous SnO₂ with a tunable ferromagnetic response through Ni loading
Fan, Junpeng (Universitat Autònoma de Barcelona. Departament de Física)
Zhang, Jin (Universitat Autònoma de Barcelona. Departament de Física)
Solsona Mateos, Pau (Universitat Autònoma de Barcelona. Departament de Física)
Suriñach, Santiago (Suriñach Cornet) (Universitat Autònoma de Barcelona. Departament de Física)
Baró, M. D.. (Universitat Autònoma de Barcelona. Departament de Física)
Sort Viñas, Jordi (Universitat Autònoma de Barcelona. Departament de Física)
Pellicer Vilà, Eva Maria (Universitat Autònoma de Barcelona. Departament de Física)

Data:	2016
Resum:	Undoped and Ni-doped ordered mesoporous SnO₂ powders ([Ni(II)]/[Sn(II)] = 0 : 100, 5 : 95, 15 : 85, 20 : 80) were synthesized by nanocasting from mesoporous KIT-6 silica. The resulting Ni content in the Ni-loaded powders ranged between 1 at% and 9 at%. Successful replication of the silica template was verified by scanning electron microscopies for all samples. Residual silicon content did not surpass 4 at%. X-ray diffraction analyses showed that the powders were nanocrystalline, being the rutile-like phase of SnO₂ the dominant structure. Changes in the lattice constants depending on the Ni content were observed, suggesting that Ni enters the rutile structure of SnO₂ to some extent. No extra phases attributed to Ni were detected in the powders except for the sample synthesized from 20 : 80 [Ni(II)]/[Sn(II)], for which NiO as secondary phase was observed. The oxidation state and spatial distribution of Ni in the powders was investigated by X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) measurements, respectively. For 6 at% and 9 at% Ni content, the presence of Ni2+ was established. The corresponding EELS mapping showed that a fraction of Ni (the one not forming part of the rutile phase) tended to accumulate at the pore edges, forming a nanometer-thick NiO layer. Compared to undoped SnO₂, Ni-containing powders exhibit a ferromagnetic response at low and room temperatures. Uncompensated spins at the surface of NiO are likely to contribute, in part, to the observed ferromagnetic properties.
Ajuts:	European Commission 648454 Ministerio de Economía y Competitividad MAT2014-57960-C3-1-R Ministerio de Economía y Competitividad RYC-2012-10839 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-1015
Nota:	Altres ajuts: China Scholarship Council (CSC)/201406220145 i China Scholarship Council (CSC)/201306250050
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Publicat a:	RSC advances, Vol. 6, Issue 106 (2016) , p. 104799-104807, ISSN 2046-2069

DOI: 10.1039/C6RA23918H

9 p, 2.2 MB

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Documents de recerca > Documents dels grups de recerca de la UAB > Centres i grups de recerca (producció científica) > Ciències > Grup de nanoenginyeria de materials, nanomagnetisme i nanomecànica (Gnm3) > SPIN-PORICS
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